6666699979 has 2 divisors, whose sum is σ = 6666699980. Its totient is φ = 6666699978.

The previous prime is 6666699967. The next prime is 6666700039. The reversal of 6666699979 is 9799966666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6666699979 - 2²¹ = 6664602827 is a prime.

It is not a weakly prime, because it can be changed into another prime (6666699929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3333349989 + 3333349990.

It is an arithmetic number, because the mean of its divisors is an integer number (3333349990).

Almost surely, 2^6666699979 is an apocalyptic number.

6666699979 is a deficient number, since it is larger than the sum of its proper divisors (1).

6666699979 is an equidigital number, since it uses as much as digits as its factorization.

6666699979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 357128352, while the sum is 73.

The square root of 6666699979 is about 81649.8620880648. The cubic root of 6666699979 is about 1882.0751925674.

The spelling of 6666699979 in words is "six billion, six hundred sixty-six million, six hundred ninety-nine thousand, nine hundred seventy-nine".